The present invention relates to a recording and reproducing system having a recording medium for storing information on recording tracks.
Various information recording and searching systems are known in the art for filing or memorizing image information in an image file. These systems search for and retrieve necessary information for display and other uses. While many of the image files in these systems are microfile files, magnetic tapes have also been used in lieu of microfilm.
Magnetic tape systems use an endless magnetic tape containing a number of recording tracks extending in the direction of movement or the longitudinal direction. In these systems, a desired recording track is selected by driving the tape while moving a magnetic head in a direction at right angles to the direction of movement of the tape. A video signal of a document or the like which is recorded in the selected recording track is selectively reproduced via the magnetic head.
In the above magnetic tape systems, index information peculiar to units of image information is also recorded with the image information. This index information is used as a search code for searching for the image information. The use of index information results in improved operation control and is very convenient. However, if many code errors occur in the index information because of the drop out of information, erroneous image information probably will be searched out and reproduced. To cope with this problem, it is common practice to provide check bits for checking for code errors. Reproduction only occurs after confirmation that the image information is free from any error. Nevertheless, even in the latter case, if many drop-outs occur, an extended period of time is required to search for the index information and find the image information.